Times will vary according to the power of your microwave.
It takes practice to perfect this timing issue. Your co-workers
would probably be glad to eat the fruits of your labor. :^)

Start by 'buttering' (Pam-ming) a cookie sheet or pizza pan. Use a 4-cup glass/pyrex measuring cup.
Add 1 cup white sugar, 1 cup raw peanuts, 1/2 cup white karo syrup, dash salt.
I usually stir at this point, although the recipe does not command it.
For the baking-challenged, Karo syrup is a corn syrup that you should
be able to find in the "baking goods" aisle of your grocery store.
Microwave on high for 6-8 minutes (6.5 in my 'wave).
Remove. Stir in 1 Tablespoon of butter. Microwave an additional ~2 minutes.
Add 1 tsp baking soda and 1 tsp vanilla. You get an interesting semi-violent chemical reaction here.
(it turns from syrup to essence of brittle at this stage)
Stir a bit, then pour onto and spread on the cookie sheet.
Let cool, then break and eat.
You'll have to lick the spoon, since some of the brittle
will harden on there. Use a wooden spoon, to avoid heat
transfer or plastic melting.